Portable devices such as smartphones, tablets, portable digital assistants (PDA), portable music players, book readers, and laptop computers have become popular devices for playing high-quality audio. Along with these devices, it is also popular to listen to and control the audio by way of a wireless device that wirelessly communicates with the portable device. Such wireless audio devices may include headsets, earphones, hearing aid devices, wearables, or car kits. Short range wireless communications for communication between the portable devices and wireless audio devices may include WiFi Direct and Bluetooth (BT). Among types of wireless communications, Bluetooth (BT) includes profiles for streaming audio between devices and for control of the state of streaming. The Advanced Audio Distribution Profile (A2DP) defines the protocols and procedures to stream high-quality mono or stereo audio between BT devices. This profile relies on Audio/Video Distribution Transport Protocol (AVDTP) to stream audio over an L2CAP channel. Since a stream represents unidirectional media data, the devices assume roles of source (SRC) and sink (SNK). The audio stream generating entity is the SRC whereas the consuming device is the SNK. The Audio/Video Remote Control Profile (AVRCP) is used in conjunction with A2DP for remote control on devices such as headphones, Car-Kits and wearable devices.
The Audio Video Remote Control Profile (AVRCP) in BT may be used to control A2DP state using different commands, notifications and events. The profile adopts the AV/C device model and command format for control messages, and those messages are transported by the Audio/Video Control Transport Protocol (AVCTP). Usage Examples are: play/pause/next/stop commands, play position change/filename change/audio volume change etc. are notifications. Similar to A2DP, AVRCP defines Controller (CT) and Target (TG) roles. The CT is a device that initiates a transaction by sending a command frame to a target and the TG is a device that receives a command frame and accordingly generates a response frame. The A2DP focuses on audio streaming while AVRCP is mainly used to control, browse media contents and its states.
A2DP profile establishes signaling and a media session between BT devices. AVRCP is a profile that is used to control (start/stop) the A2DP session and to observe progress of A2DP session, such as play progress, volume change, play file change and browsing of files.
Notifications generated by AVRCP while Bluetooth (BT) audio is streaming are huge. Even with BT audio offloaded to a BT controller, AVRCP notifications cause the host processor to awake. Subsequently, notifications generated by AVRCP consume portable device battery. Also, AVRCP Notifications are generated without user knowledge or checking status of the remote host processor.
From the perspective of the wireless audio device, the huge number of AVRCP notifications generated from the portable device causes battery drain in the low power designed wireless audio device. The portable device generates notifications without knowledge or necessity in the wireless audio device. Thus, although AVRCP Notifications are very important messages between wireless communications devices while A2DP audio streaming, there is a need to save battery consumption in the devices during notifications.
Although aspects of the present disclosure relate to Bluetooth, wireless communication by way of other standards such as WiFi Direct may benefit from reduced battery consumption by applying the aspects of the present disclosure.
The foregoing “Background” description is for the purpose of generally presenting the context of the disclosure. Work of the inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.